Kingsbury, Oblongata in Fishes. 9 



readily into the Vth nerve (Fig. 3). Likewise in Lepidosteus 

 the same tract may be macroscopicaliy recognized. 



Fasciculus conununis system. It afforded considerable pleas- 

 ure to recognize how exactly homologous the lobus vagi of 

 Ganoids^ is with the fasciculus communis of the Amphibian brain, 

 thus confirming the homology proposed by Strong. In Tel- 

 eosts, however, the homology should also be extended to the 

 lobus trigemini, when that structure exists. In certain Teleosts 

 (Nematognathi and Eventognathi as far as examined) the por- 

 tion of the fasciculus communis system associated with the pre- 

 auditory root (VII aa) is considerably developed and even 

 (Eventognathi) fuses with its fellow across the meson {Tuber- 

 culu7n impar). This it is which was termed by Mayser lobus 

 trigemini. The following table sets forth homologies the cor- 

 rectness of which will better appear later. 



The name fasciculus coimnunis first given by Osborn to this 

 structure of the Amphibian brain has been adopted by Strong, 

 Burckhardt and the writer, for Amphibia and more generally 

 applied ( in Amia ) by Allis, and seems to have become firmly 

 established. It is unfortunate that the study proceeded from 

 the Amphibia to fishes instead of in the reverse direction, since 

 when the term fasciculus is applied to other Ichthyopsida it be- 

 comes somewhat inappropriate. Therefore some hesitation was 

 felt in employing the name here. It should be remembered 

 that it is not a fasciculus but a system or region of the oblong- 

 ata. In those teleosts in which there is a distinction between 



^ The old term Ganoids is employed as a matter of convenience merely and 

 is not intended as a prejudgement of the question of recognizing them as a dis- 

 tinct group. There are however some differences in the nervous system in 

 Ganoids and Teleosts which I believe will prove to be constant. 



